West Ham United have signed fullback Razvan Rat on a free transfer from Shakhtar Donetsk, while also reportedly agreeing a £15 million fee with Liverpool for Andy Carroll.

Rat, 31, began his career at Rapid Bucharest before joining Shakhtar in 2003, and has signed an initial one-year-deal at Upton Park with the option to extend his stay at the club by up to two years.

Carroll, meanwhile, has just completed a successful loan spell at the club in which he scored seven Premier League goals in 24 appearances.

Speaking to the club's official website, manager Sam Allardyce spoke of his delight at securing Rat, revealing that he had rejected an extension at his current club in order to join the Hammers.

"I'm hugely happy that we've got a player of his experience and his character," he said. "He's been playing Champions League football this year and at the highest level for many years. Shakhtar had offered him a very good contract, but his ambition was to come and try his abilities and skills in England.

"When you hear somebody speak so positively about that, then you know they've got the mental character that's needed to do well in this division. We certainly know he's got the ability and he's at an age where he's still capable of producing at 31. He speaks perfect English, which he taught himself, and that shows the discipline and the character of the man."

On Monday, Allardyce underlined his eagerness to complete a full transfer for Carroll. But it is not yet clear if Carroll will agree to move to Upton Park and he is said to be considering his options.

Liverpool manager Brendan Rodgers wants to sell Carroll to generate extra funds to strengthen his squad for next season, while Allardyce is keen to build a team around the 24-year-old.

Carroll ended his loan spell on Sunday, following a 4-2 Premier League win over Reading, by declaring on Twitter that he had "enjoyed every minute of being at West Ham", but it is understood that he will need to be convinced to make the move permanent.

But Rodgers has made it clear that he sees Carroll, whose contract with Liverpool runs until 2016, as nothing more than a squad player, while prospects of a return to Newcastle have faded.

Carroll's form over the closing months of the season earned him a recall to the England squad for friendlies against the Ireland on May 29 and Brazil on June 2 - but he has had to pull out because of a heel injury that is likely to sideline him for around six weeks.

The forward scored six goals in his final 13 West Ham appearances, having missed a chunk of the season through injury. He was ruled out for a month with a hamstring problem shortly after joining West Ham, then suffered a nine-week lay-off after twisting his knee in November.

Meanwhile, striker Carlton Cole has revealed he will be leaving Upton Park in the summer when his contract has expired. The 29-year-old moved to East London from Chelsea following loan spells at Wolverhampton Wanderers, Charlton Athletic and Aston Villa.

Capped seven times by England, Cole confirmed the news via his official twitter page.